Next-generation sequencing identifies the mutational signature of double primary and metastatic malignancies: A case report.

We present the case of a 59-year-old Chinese man diagnosed with stage III clear cell renal cell carcinoma who developed 2 suspicious lung lesions 5 years after follow-up. Pathological evaluation revealed 2 distinct types of cancer: lung adenocarcinoma in situ and clear cell renal carcinoma with lung metastasis. Lung tissue samples were sequenced using a panel of 1267 cancer-related genes. The analysis revealed completely different molecular profiles between the 2 lung lesions and similar clonal mutations in the superior lingular lobe and kidney. This indicates multiple metachronous primary tumors.